Updated runtime files. Remove version checks for Vim older than 6.0.

runtime/syntax/xs.vim

@@ -5,20 +5,13 @@
 " Previous:    Vincent Pit <perl@profvince.com>
 " Last Change: 2013-05-12
 
-" For version 5.x: Clear all syntax items
-" For version 6.x: Quit when a syntax file was already loaded
-if version < 600
-  syntax clear
-elseif exists("b:current_syntax")
+" quit when a syntax file was already loaded
+if exists("b:current_syntax")
   finish
 endif
 
 " Read the C syntax to start with
-if version < 600
-  source <sfile>:p:h/c.vim
-else
-  runtime! syntax/c.vim
-endif
+runtime! syntax/c.vim
 
 let xs_superseded = 1 " mark C functions superseded by Perl replacements
 let xs_not_core   = 1 " mark private core functions
@@ -3249,29 +3242,21 @@ syn keyword xsMacro what_len_TRICKYFOLD_safe whichsig write xio_any xio_dirp
 syn keyword xsMacro xiv_iv xuv_uv yystype
 
 " Define the default highlighting.
-" For version 5.7 and earlier: only when not done already
-" For version 5.8 and later: only when an item doesn't have highlighting yet
-if version >= 508 || !exists("did_xs_syntax_inits")
-  if version < 508
-    let did_xs_syntax_inits = 1
-    command -nargs=+ HiLink hi link <args>
-  else
-    command -nargs=+ HiLink hi def link <args>
-  endif
+" Only when an item doesn't have highlighting yet
+command -nargs=+ HiLink hi def link <args>
 
-  HiLink xsPrivate    Error
-  HiLink xsSuperseded Error
-  HiLink xsType       Type
-  HiLink xsString     String
-  HiLink xsConstant   Constant
-  HiLink xsException  Exception
-  HiLink xsKeyword    Keyword
-  HiLink xsFunction   Function
-  HiLink xsVariable   Identifier
-  HiLink xsMacro      Macro
+HiLink xsPrivate    Error
+HiLink xsSuperseded Error
+HiLink xsType       Type
+HiLink xsString     String
+HiLink xsConstant   Constant
+HiLink xsException  Exception
+HiLink xsKeyword    Keyword
+HiLink xsFunction   Function
+HiLink xsVariable   Identifier
+HiLink xsMacro      Macro
 
-  delcommand HiLink
-endif
+delcommand HiLink
 
 let b:current_syntax = "xs"